A modal popup box would be really useful for buttons too. For example, to click on a button for 'learn more' and not have to leave the page, the lightbox would just show the additional info right there and greying out the background. Then click on big 'x' and box closes, and we still stay on the same page. Another example, would be to optin for email newsletter. Click a button for 'next' and llightbox opens mailchimp or aweber option form fields with 'submit' button. This would be just pasting in the newsletter raw html or js code.